434 



REPORT — 1887. 



Table X. — Limits of Stress from Wolders Endurance Tests. 



(Stresses in Tons per Square Inch for which Fracture occurs only after an indefinitely- 

 large Number of Kepetitions.) 



For many years tbe only experimental -work of importance being 

 carried on in connection with the endurance of metals was that already 

 referred to as inaugurated by Wuhler and continued by Sijangenberg and 

 Bauschinger ; but in this country, since the commencement of the Forth 

 Bridge works, Mr. Benjamin Baker lias been carrying on a series of experi- 

 ments with the special view of testing the effects of so-called 'fatigue' 

 on the steel used in the bi'idge as compared with hard steel and with 

 iron. 



The experiments may be classified under four beads: (1) Spindles 

 rotating with a weight at the free end, causing alternate tension and com- 

 pression on the fibres as the spindle revolves. (2) Flat bars bent in 

 some cases one way only, and in other cases both ways. (3) Specimens 

 so designed as to give alternate direct tension and compression on small 

 pieces of metal ; and (4) Full-sized riveted girders. 



Serirs No. 1. 



